Control system



Oct. 21, 1941. A. B. SIMON, JR

CONTROL SYSTEM Filed Oct. 28, 1937 QMQOJU 7 3421 02 P i! 5: 09 m2 INVENTOR BY B. SimorLJr.

zflxw ATT RNEY Patented Oct. 21, 1941 CONTROL SYSTEM Andrew B. Simon, Jr., Cleveland, Ohio, assignor to Minneapolis- Honeywell Regulator Company, Minneapolis, Minn., a corporation of Delaware Application October 28, 1937, Serial No. 171,543

9 Claims.

This invention relates to a condition controlling system and more particularly to a tempera ture controlling system of thetype wherein different predetermined temperatures are maintained in a space or spaces during different predetermined portions of a day.

In large buildings, such as schools, it is desirable to maintain the temperatures of the different rooms at one temperature during the day, or during the time that the building is being used, and to maintain a lower temperature during that portion of the day that the building is unoccupied. In order to effectively control the temperatures of the various rooms, it is usual to provide a separate controlling device for each room, and to provide a master controller for automatically causing the controlling devices to maintain a different temperature during that portion of the day that the building is unoccupied than during the portion of the day that the building is occupied.

It often happens that during the portion of the day that a lower temperature is being maintained in the building, or during the night shut-down I I g H means whereby the day temperature may be period, one or more of the rooms may be occupied, in which case a higher temperature should be maintained in these rooms during the occupied period. each of the rooms for individually, changing the controlling devices from night operation to day operation, and it is to this featurethat my invention is more particularly directed.

These individual means for changing the controlling devices from night operation today operation are so arranged that should they be operated during the day-time, as is very likely to happen when they are located in school rooms and accessible to children, they will have no efiect on the system whatever. Means are also provided so that if they are operated during the night to maintain a higher temperature in one of the rooms, that at a certain predetermined time during the night, the controlling devices will again be placed on night operation, should the occupants neglect to manually place them back on night operation upon leaving the room's.

In order to effect these results, each room is provided with a day thermostat and a night thermostat, and in a remote place, as in the basement, master controlling means are provided for placing the night thermostats in control of the heating means for each room after the building is normally unoccupied, and for placing'the Means are accordingly provided in each room are a pair of switches, one switch being adapted to place the day thermostat in control in the particular room during the night, and the other'SW'it chbeing adapted to place the night thermostat back into control during the night.

The various cont-rolling circuits are so arranged that during the day OperatiOn of the switches will not afiect the normal operation of the system. 1'0

It is accordingly an object of my invention to provide an improved condition controlling system wherein one condition is automatically maintained in a space during one portion of a day, in which a second condition is automatically 15' maintained during the rest of the day, and in which the condition normally maintained during one portion of the day may be maintained when desired during another portion of the day.

More specifically, it is an object of my invention to provide a zone temperature control system wherein a high temperature is maintained in all the zones duringthe day, in which a lower temperature is maintained during the night, in which each zone is provided with manual control maintained during 'the night in any particular zone, and in which operation of the manual control means during the day will 'not affect the temperature of any of the zones or the normal operation of the system.

shown) day thermostats in control shortly before. the l. building is to be occupied in the morning. In being normanyclosed and being adapted to open 4 0 understood that any other suitable type o'f-heat- It is a further object of my invention to provide improved means for effecting the desired results. I

Other objects will appear upon a consideration the accompanying specification, claims, and drawing.

In the drawing my invention is illustrated in schematic form. While a heating system of the direct radiation type is illustrated it should be ing system may be employed. A conventional furnace IU of the hot water or. steam type is provided and is connected with suitable radiators v IDI, ZOI, and 30! located in rooms or zones I00,

45- 200, and can by a suitable pipe II and branch pipes l2, l3, and M.

For supplying power to various electrical devices to be hereinafter described are lines 20 and 2| connectedto a suitable source of power (not Connected to the lines 20 and 2| is a step-down transformer 22 which includes a line voltage primary 23 and a low voltage secondary 24. In series With the line 20 is a time switch 25 of conventional construction, this time switch the circuit through line 20 at certain predetercooperates'with the arm I24. 1coil I2I is deenergized, as illustrated, arm I23 is in engagement with contact I26, and upon ,ener-. jgization of soil I2I, arms I23 and I24 are moved into engagement with contacts I25 and I21, re-

relay I20, are provided in the spaces 200 and 300, respectively. a I 1 I mined times during the day for a purpose to be later described. While the times during which the switch momentarily opens may be varied to suit the requirements of the system they may be taken as 7 a. m., 3:55 p. m., and 11 p. m.

Connected to one side of the secondary 24 by means of a conductor 26 is a line 21. A second line 28 is connected to the other side of the secondary 24 by means of conductors 29 and 30 and a time switch 3|, this time switch being normally open and being adapted to be momentarily closed at certain times during the day. It will therefore be seen that line 28 is connected to secondary 24 only at such timesas the time switch 3I is momentarily closed. For purposes of description it will be assumed that switch 3| closes momentarily at 4 p. m. and 11:05 p. m. Since the structure of time switches 25 and 3i forms no part of the present invention the details vof these switches have not been shown.

A second relay designated generally by the reference character I30 is provided in the space I00, said relay including a coil I3I, an armature I32 and arms I33 and I34. Cooperating with the arm I33 is a contact I35 and contacts I36 and I31 cooperate with the arm I34 When the relay I30 is deenergized arm I34 is in engagement with the contact I31, as illustrated.

Upon energization of coil I 3| the arms I33 and I34 are moved into engagement with contacts I35 and I36, respectively. Relays 230 and 330 similar to the relay I30 are provided in the 1 spaces 200 and 300, respectively.

switch arm MI and contacts I42 and I43. Sim- Also connected tothe secondary24 by means of a conductor 32 isa line 33. v v 1 Mounted in the space I00 are thermostats I02 and I03. Thermostat I02 includes abimetallic element I04, '2. contact arm I05 carried thereby and fixed contacts I06 and I01. Thermostat 403 includes a bimetallic element I08, a contact arm I09 carried thereby and fixed contacts H0 and III. Thermostat I02 is termed a'night thermostat and. thermostat I03 a day thermostat. The arms I05 and I09 are caused to move in response to temperature changes affecting the bimetallic elements I04 and I08, respectively. Arm ;I05engages contact I06 when the temperature of the space I00 drops to a predetermined low value and engages the contact I01 when the temperature ofthe space rises to a predetermined high-value. Similarly arm I09 engages contacts I I0 and III, respectively, in response tothe attainment of low' and high predetermined temperatures in'the space. The arm I05 engages its contacts at lower temperatures than that at which the arm I09 engages itscontacts. Therjmostats 203 and 303 mounted in the spaces 200 and 300 are similar to the thermostat I03 and the thermostats 204 and 304 are similar to the thermostat I04.

j For controlling the supply of heating medium to the radiator IOI is a valve H2 controlled by a valve motor H3. Motor H3 is provided with contacts H4 and I I5 which are connected to the power supply. Contacts H6, H1, and H8 are provided for controlling the current through the motor. 'When contacts H6 and H1 are con- .nected together the motor H3 is operated to cause valve H2 to close and when the contact I I5 is connected to the contact H8 the motor H3 causes the valve H2 to open. Valves 2I2 and 3I2 located in the spaces 200 and 300 are controlled by motors 2I3 and 3I3, respectively, which motors are identical with the motor H3. A relay generally designated by the reference fcharacter I20 is located in the space I00, said lrelay comprising a coil I2I, an armature I22 and relay arms I23 and I24. Contacts I and I26 cooperate with the arm I23 and contact I21 When the relay ilar switches 240 and 340 are provided for controlling the relays 239 and 330, respectively. A second switch I45 comprising an arm I46 and contacts I41 and I48 is provided for causing the deenergization of relay I30.- This switch is normally closed, as illustrated. Similar switches 245 and 345 are provided for causing the deenergization of relays 230 and 330.

Operation Let it be assumed that it is daytime, time switch 25 is in its normally closed position and time switch 3| is in its normally open position. While the operation is described more particularly with relation to zone I00 in the following 1 paragraphs it will be understood that the oper- 1 ing circuit: from one side of the secondary 24 H6 of the valve motor spectively. Relays 220 and 320, identical to the through conductor 26, line 21, conductor I50, conductor I5I, tap I I4 and tap H5 through conductors I52, I68, line 33, and conductor 32 to the other side of the secondary 24. Since tap H3 is connected to neither tap H1 nor H8, there is no circuit through the motor. Assume the temperature drops to a valve wherein the arm I09 engages contact H0. Tap II 6. is'then connected to tap H8 through the following circuit: from tap H6 through conductor I55, arm I23, contact I26,

conductors I56, I51 through the bimetallic element I08 of thermostat I03, arm I09, contact H0, conductors I58, I59 to the terminal H8 of the valve motor H3. Valve motor H3 now operates to open the valve H2 thus permitting circulation of the heating medium through the radiator IN. The temperature of the space will now commence to rise and after it has risen to a predetermined value the arm I09 will engage contact III. Terminals H6 and H1 of the valve motor H3 will now be connected through the following circuit:. from terminal I I6 through conductor I55, arm I 23, contact I26, conductors I56 and I51, bimetallic element I08, arm I09, contact I I I, conductors I 6|, I62 to the terminal H1 of the valve motor. The valve motor H3 now operates in the reverse directionto cause valve H2 to move to closed position and cut ofi' the supply of .the heating medium to the radiator IOI. It will thus be seen that with the relays in their deenergized positions, as illustrated,

that the valvemotor I3 is under the control of the. day thermostat I03.1 v I I At 4 p. m. the time switch 3| will close momentarily and energize the relay coil I-2I through the following circuit: from thesecondary 24 of transformer 22 through conductor 30, time switch 3|, conductor 29, line 28, conductors I53, I66 through the relay coil I2I, conductors I61, I50, line 21 and conductor 26 to the other side of secondary 24. Energization of coil -I2I causes arms I23 and I24 to move into engagement with contacts I25 and I26, respectively. Movement of arm I24 into engagement with contact I26 closes a holding circuit through the coil I2I which circuit is independent of the time switch 3| and is as follows-:. from the secondary '24 through conductors 32, I68, I65, contact I21, arm I24, conductor I66. through the coil I2I, conductors I61, I50, line 21 and conductor 26 to the other. side of the secondary 24. It will thus be seen that the relay I20 will. remain energize-d after the time switch 3| again opens.

The valve motor H3 is now under the control of the night thermostat I04 so that a lower temperature will be maintained in the space I00. It will of course be understood that the control of valve motors 2I3 and 3|3 in the spaces 200 and 300 will be similarly transferred to the night thermostats 204 and 304. When the temperature in the space I drops to a value low enough to cause the arm I05 to move into engagement with the contact I06, the'terminals II6'and II8 of the valve motor II3 will be connected together through the following circuit: from terminal IIO through conductor I55, arm I23,contaot I25, conductor I10, arm I34, contact I31, conductor I1I, bimetallic element I04, arm I05, contact I06 and conductors I12 and I59 to the terminal II8.- By reason of the connection of these-two terminals the valve motor II3 will operate to open the valve 2 and admit the heating medium to the radiator I0 I. When the temperature in the space I00 has risen to a value high enough to cause the arm I05 to engage the contact I01 the terminals H6 and H1 of thevalve motor II3 will be connected through the following circuit: from terminal II6 through conductor I55, arm I23, contact I25, conductor I10, arm I34, contact I31,

conductor I1I, bimetallic element I04, arm I05, contact I 01, conductors I15 and I62 to the terminal I I1. The valve motor I I3 will now be operated. in the reverse direction to cause valve II2 tomove to closed position.

As long as .relay I remains energized and relay I remains deenergized, the thermostat I04 will control the valve motor I|3v and cause a lower temperature to be maintained inthe space I00 than is maintained when the valve motor 3 is under the control of the thermostat I03. Relay I20 will remain in its energized position as long as the holding circuit through the arm I24 is maintained and this holding circuit can be interrupted only by cutting off the source of power. This will occur at 11 p. m. by the time switch 25 but since the time switch 3| is momentarily closed at 11:05 p. m., the relay I20 "again becomes energized, The reason for switch ,25

' opening at 11 p. m. and switch 3| closing at 11:05 p. m. will be subsequently explained. At

elf)

7 a. m. the switch 25 again opens momentarily which interrupts the holding circuit through the arms I24 thus causing relay I20 to become deenergized whereupon the valve motor I I 3 is again under the control of the day thermostat I03. It will 'of course be understood that the switches 25 and 3| affect the relays 220 and 320 in exactly the same manner as they do the coil I20 s'o'th'at these zones are simultaneously placed under the control of the day thermostatsor the night thermostats Assume now that the time switch 3| has operated so that the valvemotors are all under the control of the'nig'hti thermostats, the time being subsequent to 4 p. m. If it is desired to occupy one of the rooms such as thero'om I00 it will be desirable to maintain a higher temperature in this room than would be maintained by the night thermostat. .In order to place the motor I I 3 again under the control of the day thermostat I03 it is merely necessary to momentarily move the switch arm I4| into engagement with the contacts I42 and I43, respectively, causing a circuit to be established through the relay coil I3| which is as follows: from one side of the secondary 24 through conductors 32, line 33, conductor I80, contact I43, the switch arm I4I, contact I42, conductors IBI, I82 through the coil I3I, conductor I83, line 21, and conductor 26 to the other side of the secondary 24. A holding circuit is also established throughthe coil |3I which is independent of the switch I40, this circuit being as follows: from the secondary 24 through conductor 32, line. 33, conductor I80, contact I41, switch blade I46, contact I48, conductor I85, contact I35, arm I33 which has moved into engagement with contact I35 upon the energization of coil I 3|, conductor I82 through the coil I3I, conductor I83, line 21, and conductor 26 to the other side of secondary 24. Energization of coil I3| causes thev arm I34 to move into engagement with contact I36 so that the valve H3 is again under the control of the thermostat I03 as explained below.

Upon a call for heat by thermostat I03, arm I09 will move into engagement with contact H0 and closing a circuit between terminals II6and IIB of motor II3, which circuit is as follows, it being remembered that both relays I20 and I30 are now energized: from the terminal I I6 through conductor I55, arm I23, contact I25, conductor I10, arm I34, contact I36, conductors I86, I51, bimetallic element I08, arm I09, contact I I0, conductors I58 and I59 to the terminal H8. The valve I I2 is now moved into open position whereupon the heating medium is supplied to the radiator IOI. When the thermostat I03 becomes satisfied, arm I09 will engage contact III and connect terminals H6 and 1 through the following circuit: from terminal II6 through con ductor I55, arm I23, contact I25, conductor I10, arm I 34, contact I36, conductors I86 and I 51, bimetallic element I03, arm I09, contact III, conductors I 6| and I62 to the terminal II1. Thus as long as both relays I20 and I30 are energized the valve motor H3 is under the control of the day thermostat I03. It will thus be seen that during the night-time when the valve motors are normally under the control of the night thermostats, that the valve motor in any one or more 1 zones may be placed under the control of the day thermostat by op'erationof switches I40, 240, or 340.

Since energization of the relay coil |3I is through the holding circuit which includes the switch I45, opening of this switch will cause the relay I30 to become deenergized and if the relay I20 is still energized the valve motor II3 will again be under the control of the'night thermostat I02. In the normal operation of the system, it is intended that the occupant of any one of the zones during the night should operate the switch I45 in zone I00, or the corresponding switches in the valve motor II 3;

resume control over that particular zone. J Should switch 3I. momentarily closes which again energizesthe relay coil I through the circuitpreviously described. Since energization of relay coil I3] is dependent upon the manual operation of switch I40 it will bejapparent that this operaltion of the time switches and 3| in theorder ,specified, will cause both relay coils to be deener- .gized and relay I20 to again become energized thus placing the valve motor 3 under the control of thermostat I02.

Should the occupant of the zone during the might desire to remainafterll p. m. at which 7 1 time the night thermostat automatically resumes control over the system a second manipulation of switch .140 will again place the valve motor I I3 under the control of theday thermostatas previously described. Uponjleaving the zone the occupant should manipulate. the switch I45 thus I placing the valve motor again under the control 1 of the night thermostat I04. Should he fail to'do I this, novharm will result and the system will resume normal operation the following day.

Assuming now that the valve motor I I3 is under 1 the control of the night thermostat I02, relay I20 being energized and relay I being deenergized,

the valve motor will be..automatically placed lunder the control. of theday thermostat at 7 1a. m. at which time the switch 25 momentarily }opens, interrupting the supply of power to the l transformer 22, thus breaking.- the holding circuit through the relay I20. If for any reason during the day switch I40 3 is operated to close the contacts I42 and I43 as is likely to happen, particularly in a school room, 1 the relay I30 will become energized but this will not have any effect upon the control of thermo l stat I03 over the valve motor II3. If this relay 3 I30 should remain energized throughout the day Bit. should be deenergized before the night shut- 3 down since otherwise when relay I20 becomes energized the'thermostat I03 would still exercise control over the valve motor. For this reason the time switch 25' momentarily. breaks the circuit through the line 20, thus causing deenere 1 gization of relay I30 by interrupting the holding circuitas previously described, so that when at 4 oclock the time switch 3I'momentarily closes, the relay 120 will become energized and since relay I30 has just previously been deenergized the night thermostat, I02 will exercise control, over It is therefore seen that the day operation of the system will not be in any 1 way affected by tampering of the switches I40, 240, or 340 and that the system will automati- 1 cally go on its proper night operation regardless of what'may have been done to the switches durfing the dayetime. I

Having described the preferred embodiment of my invention it should be understoodthat this is j for purposes of illustration only andthat my inv vention is to be limited onlyrby the' 'scopeof the appendedclaims. v f I 7 1' Iclaim asmyinvention: r' 3 .l. 'In'a' isystem of the class'described; a pair of 2 the other zones, when the'ro'om' is vacated for the night sothat'the night thermostat will'again tain a difierent temperature iin' -th'e s ace being controlled, a pair of relays, time controlled means 'periodically causing the energization and d-ee'ner gizati on ofone ofsaid relays, manual means controlling the' energiz'ation" of said other relay, means wheneby the first thermostat is in control of :the temperature "changing device when neither relay is energized, means whereby the second thermostat is in control of the temperature changing device when said one relay is energized,

and means whereby the first thermostat is in control ofthe temperature changing device when both relays are energized, said time controlled means including means for automatically deenergizing'both' of said relays at a'predetermined time during the period that saidrelay is normally en-;

ergized and for shortly thereafter causing the energization of said one relay only whereby said second thermostat is again placed in control of the temperature changing device regardless of the previous operation of said manual means.

r 2. In-a temperature control system, tempera? ture responsive means-temperature changing means under the control of the temperature re-H sponsive means, means controlling the temperature responsive means whereby different temperatures are automatically maintained in the space being controlled during the day and night, manual' means for causing the temperature responsive means to maintain thedaytemperature during, the night, second manual means for causing the systemto revert to normal operation during the night after operation of the first manual means, and means operative during the night for automatically causing the .system to revert to normal night operation at a predetermined time after the beginning of night operation.

3. :In a zone temperature control system, a plurality of zones whose temperature is 'to be controlled, temperature control means for each zone, means for automatically operating said temperature control means whereby one predetermined temperature is maintained in said zones during one portion'of a day and whereby a second predetermined temperature is maintained in the zones during a second portion of the day, manual means in each zone for causing operation of the temperature control means to maintain in that zone the temperature during said one portion of the day normally maintained during the other portion of the day, and a single means for automatically operating at a predetermined hour during said one portion of the day each of the temperature control means which were manually caused to'maintain a different temperature toagain maintain in all the zones the temperature normally maintained during said portion of the day Y -4. In a temperature control system, a space whose temperature isto be controlled, tempera-' ture control means for said space, means for au-' tomatically operating said temperature control means whereby one predetermined temperature is maintained in said spaceduring one portion of the day and whereby a second predetermined temperature is maintained in said space during a second portion of'the day, manuallyoperated means,forcausingroperation of the temperature.

control means to maintain in the space the temperature during said one portion of the day normally maintained during the other portion of the day, and means for automatically operating the temperature control means at a predetermined time after the beginning of said one portion of the day to again maintain in said space the temperature normally maintained during said portion of the day. i

5. In a system of the class described, condition changing means for a space, a pair of condition responsive devices responsive to a condition being controlled in the space in control of said condition changing means, said condition responsive devices arranged to be selectively placed in control of the condition changing means to maintain selectively dififerent conditions in the space, first and second relay means, circuit connections for placing one of said condition responsive means in control of the condition changing means when neither of the relay means nor both of the relay means are energized, means for placing the other of said condition responsive means in control of the condition changing means when the first only of said relay means is energized, normally open switch means, circuit connections operative upon momentary closure thereof to energize and maintain energized said second relay means, first timing means operative to periodically cause the energization of said first relay means, 'and second timing means operative to periodically cause the deenergization of both of said relay means.

6. In a system of the class described, temperature changing means for a space, space temperature responsive means in control of the temperature changing means and arranged to control the temperature changing means to maintain one of two predetermined temperatures within the space, first and second relay means, means for causing the temperature responsive means to control the temperature changing means when both relay means are energized or when both relay means are deenergized to maintain one predetermined temperature in the space, means for causing the temperature responsive means to control the temperature changing means to maintain a second predetermined temperature in the space when the first only of said relay means is energized, normally open switch means, circuit connections operative upon momentary closure thereof to energize and maintain energized said second relay means, first timing means operative to periodically cause the energization of said first relay means, and second timing means operative to periodically cause the deenergization of both of said relay means.

7. In a zone temperature control system, a plurality of zones whose temperature is to be controlled, temperature control means for each zone adapted to maintain the zone temperature selectively at either of two values, means in each zone for selecting the temperature value to be maintained therein, clock means for simultaneously operating all said selecting means, manual means in each zone eifective only after said clock means has selected the lower of said two values to operate said selecting means, whereby the temperature level in any zone may be selected by a person therein, said clock means operating in the morning to select the higher of said two values for all zones, in the evening to select the lower of said two values for all zones, and at a predetermined time after said evening operation to select said high value, thereby rendering said manual means inefiective, and immediately thereafter to select said low value for all zones.

8. In a zone temperature control system, a plurality of zones whose temperature is to be controlled, temperature control means for each zone adapted to maintain the zone temperature selectively at either of two values, means in each zone for selecting the temperature value to be maintained therein, manual means in each zone for operating said selecting means, and clock means for operating all said selecting means simultaneously at predetermined intervals, said clock means being efiective when operating said selecting means in one sense to render all said manual means ineffective, and effective when operating said selecting means in the opposite sense to maintain each zone at the temperature value selected by said manual means.

9. In a condition controlling system, a pair of condition responives devices, condition changing means under the control of said condition responsive devices, a pair of control means, time controlled means for periodically causing the energization and deenergization of one of, said control means, manual means for controlling the energization of said other control means, means whereby one of the condition responsive means controls the condition changing means when neither of said control means is energized, means whereby the other condition responsive means controls the condition changing means when said one of said control means is energized, and means whereby said one condition responsive means controls the condition changing means when both of said control means are energized, said time controlled means including means for automatically adeenergizing both ofsaid control means at a predetermined time during the period that said one control means is normally energized and for shortly thereafter causing the energization of said one control means only whereby said other condition responsive means is again placed in control of the condition changing means regardless of the previous operation of said manual means.

ANDREW B. SIMON, JR. 

